I just dumped 6 gallons of contaminated brew in my secondary fermenter. It was fine in the primary and I'm sure the sanitization was fine with all equipment. I'm suspecting the dry hop sack (leaf hops)... Curious to know if anyone out there has experienced contamination from dry hopping?

I've dry hopped 4 out of 5 batches so far and no issues yet...though I do not use the hop sack in the vessel...I use it as a filter on the end of my racking tube when transferring to the bottling bucket.

This method works really well for whole leaf hops, yet still allows suspended yeast to pass through for bottle conditioning. Prior to that, the sack sits in sanitizer for a while.

I dry hop my IPA's in the secondary all the time....never had an issue. I don't worry so much about the hops being a source of contamination, but I take care to boil the knee high stockings that I use to hold the hops.